value of attribute %2 cannot be %1; must be one of %3

Cause:

The value of the attribute is defined to be one of a list of possible values but in the document it contained something that is not allowed for that type of attribute. For instance, the “selected” attribute must be either minimized as “selected” or spelled out in full as “selected="selected"”; a value like “selected="true"” is not allowed.

Example:

textexample textexample

Bad:
textexample
textexample
Good:
textexample textexample

Solution:

textexample textexample

References: